What type of color application technique involves using foils?

The type of color application technique that involves using foils is highlighting. This method is specifically designed to add dimension to the hair by lightening particular sections, which are typically isolated with foil. The foils help to create a more controlled environment, allowing the color to develop without affecting the surrounding hair.

In contrast, balayage is a freehand painting technique that doesn’t use foils, which allows for a more natural, sun-kissed look as the stylist applies the color directly to the hair without any barrier. Ombre is characterized by a gradient effect, transitioning from a darker color at the roots to a lighter shade at the ends, usually applied without foils. Global color refers to a uniform application of hair dye all over the head for a single color result, which typically doesn't involve using foils either. Highlighting stands out because it requires foils to achieve well-defined, separated lighter strands.